I have been building and repairing computers for the last 20 years. The case that you have for your Pentium 4 PC will work fine for your new motherboard. However, you'll need to change out your power supply and maybe you'll need to upgrade your DVD ROM drive from an IDE to a SATA. This will hold true for your hard drives too they will also need to be SATA. Older computers and motherboards used an IDE cable. When you take out your old motherboard make sure that you remove the mounting plate at the back of the machine so you can install the new one in the same place.